from twisted.internet.protocol import DatagramProtocol
from twisted.internet import reactor
class MulticastPingPong(DatagramProtocol):
def startProtocol(self):
"""
Called after protocol has started listening.
"""
# Set the TTL>1 so multicast will cross router hops:
self.transport.setTTL(5)
# Join a specific multicast group:
self.transport.joinGroup("228.0.0.5")
def datagramReceived(self, datagram, address):
print "Datagram %s received from %s" % (repr(datagram), repr(address))
if datagram == "Client: Ping":
# Rather than replying to the group multicast address, we send the
# reply directly (unicast) to the originating port:
self.transport.write("Server: Pong", address)
# We use listenMultiple=True so that we can run MulticastServer.py and
# MulticastClient.py on same machine:
reactor.listenMulticast(8005, MulticastPingPong(),
listenMultiple=True)
reactor.run()